Three-pole, metal-encased, pressurized-gas-insulated, high-voltage switchgear

ABSTRACT

A three-pole, metal-encased, pressurized-gas-insulated, high-voltage switchgear may include a single-pole, encapsulated, high-voltage power switch. Breaker units are located in a pressure chamber and are arranged with longitudinal axes thereof parallel to one another, and are attached to a bearing component which also carries the casing of the drive. In order to increase the mechanical rigidity of the bearing component, a shared gear casing with two partitions is provided for the switching mechanism, to which the breaker units are attached via bearing rings. The bearing rings, held by bridges, lie in front of three apertures on a side wall of the gear casing, to the flanges of which the pressure chambers are also attached. In the interior of the gear casing, carriers for the bearings of the drive shafts are provided, which proceed from the partitions or an outer wall. All bearing and sealing surfaces of the gear casing lie in parallel planes in each case, and can be machined in a single clamping process. The shared gear casing for the switching mechanism is suitable for single-pole, encapsulated, pressurized-gas-insulated, high-voltage power switches of three-pole, metal-encased, pressurized-gas-insulated, high-voltage switchgears.

BACKGROUND OF THE INVENTION

The invention relates to a three-pole, metal-encased,pressurized-gas-insulated, high-voltage switchgear with a single-pole,encapsulated, high-voltage power switch, with several breaker unitslying next to each other, encapsulated with one pole in pressurechambers, which are each attached to a bearing component which isconnected with a casing of the drive and of the switching mechanism, andthe parallel axes of which run parallel to each other.

From FR 20 89 315, a multi-pole, encapsulated high-voltage switch withseveral breaker units lying next to one another in a shared casing isknown, in which the switching mechanism is also housed in the samecasing as the breaker units. The breaker units are each connected withthe shared casing at their two ends, so that complicated disassembly isrequired for maintenance.

It is known, especially from CH-PS-558 094, to encapsulate the poles ofthe power switch of a three-pole, metal-encased,pressurized-gas-insulated, high-voltage switchgear in single-pole mannerin each case, so that the breaker units of each pole are each housed ina separate pressure chamber, which is closed off by a cover on thefrontal side.

From CH-PS-648 152 (cf. there particularly FIGS. 1 to 4), a multi-pole,metal-encased, pressurized-gas-insulated high-voltage switchgear of thetype stated initially is known, in which the pressure chambers of theindividual breaker units are each rigidly connected with the shared gearcasing. There, the breaker units are each attached individually, in theindividual pressure chambers.

SUMMARY OF THE INVENTION

The present invention is based on producing a mechanically more rigidconnection of the breaker units relative to each other in a three-pole,metal-encased, pressurized-gas-insulated high-voltage switchgear.

To accomplish this task, it is provided, according to the presentinvention, in a pressurized-gas-insulated, high-voltage switchgear ofthe type described initially, that the breaker units are attached withbearing surfaces on the frontal side, on a shared gear casing whichcontains the switching mechanism of the drive, and can be moved relativeto the pressure chambers, if necessary, the interior of which is dividedinto three sections, each assigned to a breaker unit, by two partitions,and the pressure chambers of the individual breaker units are connectedwith the gear casing via three flanges, each having an aperture, to forma gas seal, and that bearing rings for attachment of the breaker unitsto the gear casing are provided, which are connected with the gearcasing via bridges which pass through the apertures.

With the bearing attachment of the breaker units to the shared gearcasing and its strengthened structure due to the interior walls, it isensured that the breaker units are attached in their position in such away as to be easily adjustable and reliably attached. The gear casinghas the form of a hollow carrier because of its essentially cuboidshape, which in itself already has great mechanical rigidity. Thebreaker units can be pulled out of the pressure chambers together withthe gear casing, or pushed into them, for adjustment or maintenancework. This is advantageous, for example, also for the first assembly.

The region of each breaker unit which is filled with insulating gasextends beyond the pressure chambers to the gear casing in this design.In this way, no gas-sealed slide passage has to be provided at thecoupling point between the pressure chambers and the gear casing, forthe drive of the breaker unit. In addition, the flow-off space assignedto each breaker unit for the insulating gas is enlarged with thismeasure, so that pressure increases as the result of arc effects areattenuated by the enlargement of the volume.

The breaker units are attached to bearing rings, which in turn are heldby the bridges attached on the inside of the gear casing. In this way,the breaker units can be attached to the gear casing without anyattachment with the flanges The breaker units can thus be pulled out ofthe inside of the high-voltage switchgear by retraction of the gearcasing through the flange openings of the pressure chambers

Furthermore, the invention can be advantageously structured in that thesealing surfaces of the flanges lie in one plane.

This has the effect that the sealing surfaces on the gear casing can bemachined during a single clamping process in its production. In thisway, the production tolerances in the production of the gear casing arelimited.

Also, for the purpose of enlarging the insulating gas volume availableto each breaker unit, it can be advantageously provided that thesections of the gear casing are connected with each other viaequalization apertures.

The equalization apertures are sized and positioned in such a way thatthey permit the exchange of insulating gas between the different breakerunits, on the one hand, but on the other hand keep the effects of an arcin one of the breaker units away from the other breaker units.

The invention can furthermore also be advantageously structured in thatthe partitions of the gear casing have carriers for bearings of driveshafts. In this way, uncomplicated but stable design of the gear casingis made possible.

It is recommended that assembly apertures, which can be closed off bycovers, be provided on the side wall of the gear casing opposite theflanges, the center axis of which is laterally shifted relative to thelongitudinal axis of the breaker units. In this way, good accessibilityto the interior of the gear casing is guaranteed, even after thepressure chambers and the breaker units are installed, which simplifiesattachment of the parts of the switching mechanism to the switch rod andtheir alignment, for example.

When sections of the interior of the gear casing are connected with eachother, it is furthermore advantageous to provide a shear plate in onecover of the three assembly apertures, with which an overly highpressure increase is prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be explained in greater detail onthe basis of the embodiment shown in FIGS. 1 to 5, to which theinvention is not restricted, however.

FIG. 1 shows a longitudinal cross-section through the gear casing andthrough part of the subsequent pressure chamber and breaker units of thepower switch connected with it, in a schematic representation,

FIG. 2 shows the corresponding top view, and

FIG. 3 shows a top view of the outside side surface only of the gearcasing alone, without connected parts, which is cut along the lineIII--III in FIG. 1, along with a partial cross-section, and in theclaims.

FIG. 4 shows a top view of the first side wall of the gear casing alone,in partial cross-section, and

FIG. 5 shows a view of the gear casing, in partial cross-section,together with the breaker units and pressure chambers connected with it.

DETAILED DESCRIPTION

A three-pole, metal-encapsulated high-voltage switchgear insulated withpressurized gas, especially SF₆, has a single-pole, encapsulated,pressurized-gas-insulated power switch 1, especially a pressurized gasswitch. The breaker units 2 of each pole are each located in a separategas space 3, which is formed by pressure chambers 4, and are carried bya hollow support insulator 5. They are each arranged in their pressurechambers 4 with longitudinal axes 6, indicated with broken lines,parallel to one another.

To activate the switching contacts, not shown, of the high-voltage powerswitch 1, there are two opposite switch rods 7, which pass through thehollow support insulator 5. These switch rods 7 are connected with thefork lever of the switching mechanism 9 at their end 8 facing away fromthe switching contacts, which mechanism is housed in a shared gearcasing 10 for all three poles of the high-voltage power switch 1.

The shared gear casing 10 has an approximately cuboid shape, which issimilar to a hollow carrier. The interior of the gear casing 10 isdivided into sections 12 each assigned to a breaker unit 2. The gearcasing 10 therefore has great mechanical rigidity. It forms the bearingcomponent for the breaker units 2 of the three poles of the high-voltagepower switch 1 and also serves for attachment of its pressure chambers4. This is independent of whether these pressure chambers 4 areconnected with each other, also reinforcing each other.

On the first side wall 13 of the gear casing 10, three apertures 14 areprovided, which are surrounded by flanges 15, the sealing surfaces 16 ofwhich are aligned in one plane. The frontal flanges 17 of the pressurechambers 4 are attached at these sealing surfaces 16, forming agas-tight seal. In front of the apertures 14, there is furthermore abearing ring 18 in each case, which is held at a distance from theapertures 14 by bridges 19. These bridges 19 proceed from the insidesurfaces of the walls of the gear casing 10 and pass through theapertures 14. On the bearing rings 18, there are bearing surfaces 20 ineach case, which are also in one plane, which extends parallel to theplane of the sealing surfaces 16. The flange 21 of the hollow supportinsulator 5 and thus the breaker units 2 are attached at these bearingsurfaces 20.

In each section 12 of the gear casing 10, there are furthermore carriers22, 22a provided, which serve as bearings for the drive shafts 23, 23afor the switching mechanism 9. This drive shaft 23, 23a runsperpendicular to the longitudinal axis 6 of the breaker unit 2 in eachcase, and is arranged with lateral offset in the same direction in eachsection 12, relative to this axis. As a result, the carriers 22 for twoof the three drive shafts 23 proceed from the partition 11, while thethird carrier 22a for the third drive shaft 23a proceeds from an outsidewall 24 of the gear casing 10. The drive shafts 23, 23a each are passedto the outside via a second side wall 25 of the gear casing 10 (FIG. 3).

The partitions 11 inside the gear casing 10 each have two regions 27, 28which run parallel, shifted laterally in the same direction relative tothe longitudinal axis 6 of the breaker units 2, connected by a step 26.The first region 27 opens into the first side wall 13 and is offset inthe direction of the outside wall 24 relative to the second region 28,which wall has the carrier 22a for the one bearing 29 of the drive shaft23a. The carriers 22 for the two other bearings 30 of the drive shaft 23each proceed from the step 26 of the partition 11.

The first region 27 of the partition 11 is offset laterally to theadjacent section 12 to such an extent that it projects into the regionbehind the aperture 14 there. In this manner, an aperture 31 can beproduced by milling in this region 27 of the partition 11, in simplestmanner. The aperture 31 connects the separate sections 12 of theinterior of the gear casing 10 with each other in each case, so thatthese form a shared gas space. So that the openings 31 have as large anarea as possible, the step 26 of the partition 11 with the carriers 22is arranged off-center in the direction of the outside side wall 32 ofthe gear casing 10, seen in the longitudinal direction 6 of the breakerunits 2 in each case.

In this outer side wall 32, three assembly apertures 34, 34a which canbe closed off with covers 33 are provided. The center axis 35 of theassembly apertures 34, 34a is shifted laterally towards the secondregion 28 of the partition 11 relative to the longitudinal axis 6 of thebreaker units 2. Due to the assembly apertures 34, 34a, the end 8 of theswitch rods 7 is easily accessible, so that the fork lever of theswitching mechanism can be attached to the switch rods 7 in a simplemanner, and these can be aligned precisely, even if the breaker units 2are already arranged on the carrier ring 18.

Since the interior of the gear casing 10 forms only a single gas space,due to the openings 31 formed in the partition 11 due to subsequentmachining of the partition 11, it is sufficient that only the centerassembly aperture 34a is provided with a cover 36, which contains ashear plate.

Furthermore, holder plates 37 for filter material are attached in allthree sections 12 of the gear casing 10, on the inside surface at thefoot of a bridge 19.

Furthermore, connection surfaces 38 are provided on the outside sidewall 32, lying in one plane, to which drive casings or a carrier element39 for additional drive components can be attached.

The connection surfaces 38 on the outside side wall 32 and the sealingsurfaces 40 for the covers 33, 36 of the assembly apertures 34, 34a eachlie in one plane, whether in the same or parallel planes, which in turnrun parallel to the planes of the sealing surfaces 16 of the flanges 15and thus also parallel to the connection surfaces 20 on the carrierrings 18. This results in significant simplification in the productionof the shared gear casing 10, since all these surfaces can be machinedin a single clamping process of the gear casing 10. Therefore thesesurfaces also demonstrate the same production tolerances relative toeach other in each case.

The same holds true for the holder surfaces for the bearings 29, 30 ofthe drive shafts 23, 23a on the carriers 22, 22a. A shared drive is usedfor all three poles of the high-voltage power switch 1 (see FIG. 2). Thedrive, not shown, is passed via a drive rod 41 to a crank 42 connectedwith a drive shaft 23, which crank in turn is connected with the cranks44 and 45 of the two other drive shafts 23, 23a, via a simple couplingrod. Because of the same production tolerances for bearings of all threedrive shafts 23, 23a, special setting and adaptation possibilities ofthe coupling rod 43 can be eliminated.

The shared gear casing 10 for the switching mechanism 9 for activationof the switch contacts of the breaker units 2 of the high-voltage powerswitch 1 therefore forms a mechanically rigid bearing component both forthe breaker units 2 and for their pressure chambers 4. In thisconnection, the flanges 17 of the pressure chambers 4 are attached tothe flanges 15 of the gear casing 10, and the breaker units 2 areattached to the carrier rings 18 via the flange 21 of the supportinsulator 5, which rings in turn are carried by the bridges 19 and bythe gear casing 10. The stresses on the gear casing 10 which proceedfrom these attachments are thus absorbed by spatially separate regionsof the gear casing 10. Since the connection leads 46 of the breakerunits 2, which each lead to the other parts of the high-voltageswitchgear, are structured as plug connections (see FIG. 5), the breakerunits 2 still attached to the gear casing 10 can be moved together withthe gear casing 10 for service purposes. For this purpose, the pressurechambers 4 are first separated from the flanges 15.

In addition, the sections 12 of the interior of the gear casing 10 eachform additional gas spaces, the volume of which adds to the volume ofthe gas spaces 3 in the pressure chambers 4, so that in case of possibleinterference arcs, the pressure increase in these gas spaces 3 isreduced. If apertures 31 are provided in the partitions 11 of the gearcasing 10, this buffer effect is further strengthened, because a sharedgas space is formed. Thus, advantages are achieved with this shared gearcasing 10 which is provided for the three single-pole encapsulatedbreaker units 2 not only in a mechanical respect and a design respect,but also in an electrical respect.

What is claimed is:
 1. A three-pole, metal-encased,pressurized-gas-insulated, high voltage switchgear with a single-pole,encapsulated, high-voltage power switch, wherein breaker units of eachpole are located in pressure chambers and arranged with parallellongitudinal axes, and are each attached to a bearing component which isconnected with a casing of the drive and of a switching mechanism, theswitchgear comprising:a shared gear casing for the switching mechanismof the drive, an interior of which is divided by two partitions intothree sections, each assigned to a breaker unit; three apertures on afirst side wall of the shared gear casing which are surrounded byflanges with sealing surfaces lying in a common plane, to which thepressure chambers of the breaker units are attached; a bearing ring infront of each of the apertures and held at a distance by bridges of thegear casing which pass therethrough, to which the breaker units areattached; and in each of the three sections, carriers to hold bearingsof the drive shaft which each run perpendicular to a longitudinal axisof a respective breaker unit and are arranged with lateral offsetrelative to this axis in each section, and are passed to the outside viaa second side wall of the gear casing, wherein the carriers proceed fromthe partitions or an outer wall.
 2. A three-pole, metal-encased,pressurized-gas-insulated, high voltage switchgear according to claim 1,wherein the three sections of the gear casing are connected with eachother.
 3. A three-pole, metal-encased, pressurized-gas-insulated, highvoltage switchgear according to claim 1, wherein each partition has tworegions shifted laterally in a same direction relative to thelongitudinal axis of the breaker units and connected by a step, where afirst of the two regions opens into the first side wall and is offset inthe direction of the outer wall relative to the second region, whichwall has one bearing of the drive shaft, and that the carriers for twoother bearings of the drive shaft are each located on the step.
 4. Athree-pole, metal-encased, pressurized-gas-insulated, high voltageswitchgear according to claim 3, wherein the first region of eachpartition projects into the aperture of the adjacent section located inthe first side wall of the gear casing.
 5. A three-pole, metal-encased,pressurized-gas-insulated, high voltage switchgear according to claim 3,wherein apertures are located in the first region of each partition. 6.A three-pole, metal-encased, pressurized-gas-insulated, high voltageswitchgear according to claim 3, wherein the step of each partition isarranged in the gear casing off-center in the longitudinal direction ofthe breaker units.
 7. A three-pole, metal-encased,pressurized-gas-insulated, high voltage switchgear according to claim 1,wherein three assembly apertures which can be closed off with covers areprovided on an outer side wall which is located in front of the firstside wall, the center axis of the three assembly apertures being shiftedlaterally relative to the longitudinal axis of the breaker units.
 8. Athree-pole, metal-encased, pressurized-gas-insulated, high voltageswitchgear according to claim 7, wherein at least one of the covers ofthe assembly apertures contains a shear plate.
 9. A three-pole,metal-encased, pressurized-gas-insulated, high voltage switchgearaccording to claim 1, wherein connection surfaces which lie in a commonplane are provided on an outer side wall which is located in front ofthe first side wall, for casings or carriers of additional drivecomponents.
 10. A three-pole, metal-encased, pressurized-gas-insulated,high voltage switchgear according to claim 1, wherein the three bearingrings have bearing surfaces for attachment of the breaker units, thebearing surfaces lying in a common plane which is parallel to the planein which the sealing surfaces lie for attachment of the pressurechambers of the three breaker units.
 11. A three-pole, metal-encased,pressurized-gas-insulated, high voltage switchgear according to claim 9,wherein three assembly apertures which can be closed off with covers areprovided on the outer side wall, the center axis of the three assemblyapertures being shifted laterally relative to the longitudinal axis ofthe breaker units.
 12. A three-pole, metal-encased,pressurized-gas-insulated, high voltage switchgear according to claim11, wherein the connection surfaces of the outer side wall and sealingsurfaces for the covers of the assembly apertures lie in a common planeor in parallel planes, which run parallel to the sealing surfaces of theflanges.